Auto: abcip-4.1 — per-tag scan rate / scan group bucketing

Closes #238

src/ZB.MOM.WW.OtOpcUa.Driver.AbCip/AbCipDriverFactoryExtensions.cs

@@ -84,7 +84,9 @@ public static class AbCipDriverFactoryExtensions
                     Writable: m.Writable ?? true,
                     WriteIdempotent: m.WriteIdempotent ?? false))]
                 : null,
-            SafetyTag: t.SafetyTag ?? false);
+            SafetyTag: t.SafetyTag ?? false,
+            // PR abcip-4.1 — per-tag scan rate override; null means "use subscription default".
+            ScanRateMs: t.ScanRateMs);
 
     private static T ParseEnum<T>(string? raw, string? tagName, string driverInstanceId, string field,
         T? fallback = null) where T : struct, Enum
@@ -169,6 +171,15 @@ public static class AbCipDriverFactoryExtensions
         public bool? WriteIdempotent { get; init; }
         public List<AbCipMemberDto>? Members { get; init; }
         public bool? SafetyTag { get; init; }
+
+        /// <summary>
+        ///     PR abcip-4.1 — optional per-tag publish-rate override (in milliseconds). When
+        ///     present, the driver places this tag in its own <see cref="Core.Abstractions.PollGroupEngine"/>
+        ///     bucket so it ticks at <c>ScanRateMs</c> regardless of the subscription's default
+        ///     publishing interval. <c>null</c> uses the default — back-compat with deployments
+        ///     that don't set the knob. Mirrors Kepware's "scan classes" model.
+        /// </summary>
+        public int? ScanRateMs { get; init; }
     }
 
     internal sealed class AbCipMemberDto